REDES DE ARMAZENAMENTO E ALTA DISPONIBILIDADE

Transcription

1 REDES DE ARMAZENAMENTO E ALTA DISPONIBILIDADE O que é SAN? SAN Storage Área Network Rede de armazenamento. É uma rede de alta velocidade dedicada que possui servidores e recursos compartilhados de STORAGE (equipamentos de alocação de espaço em disco). Infraestrutura física de fibra ótica 1,2,4 ou 8Gbs. O acesso aos dados se dá como block-level (não provê arquivos, e sim blocos de disco) Consolida os recursos de forma centralizada facilitando o gerenciamento. A escalabilidade teórica chega a 15 milhões de devices (servers and STORAGEs). Alta segurança de acesso. Nos casos de equipamentos HIGH END disponibilidade de 24x7x365. 1

2 Termos de SAN: FC Fibre channel FCP Fibre channel protocol SCSI3 over fiber FCIP Fibre Channel sobre IP FCoE Fibre channel over Ethernet WWN Wide world number. Dividido em duas partes WWNN e WWPN Node number e Port number HBA Bus adapter NAS Network attached storage DAS Direct attached storage CAS Content address Storage SAN Storage area network HOST Servidor ou outro cliente de STORAGE INITIATOR HOST que recebe o provisionamento TARGET STORAGE que provisiona espaço de armazenamento RAID Redundant array of independent disks FA Front end adapter controladora de conexão de hosts do storage BA Back end adapter controladora de discos do storage ELEMENTOS REQUERIDOS DE UM DATACENTER PARA AS EMPRESAS Disponibilidade Integridade Segurança Gerenciabilidade Performance Capacidade Escalabilidade 2

3 Applications runs on hosts s can range from simple laptops to complex server clusters Physical components of host CPU Storage Disk device and internal memory I/O device to host communications Network Interface Card (NIC) to storage device communications Bus Adapter (HBA) Server Laptop LAN Group of Servers Mainframe - 5 : Logical Components Applications Operating System File DBMS System Volume Manager Device Drivers HBA HBA HBA - 6 3

4 Disk Drive Components HDA Interface Power Connector - 7 Physical Disk Structure Spindle Sector Track Sector Cylinder Track Platter - 8 4

5 Logical Block Addressing Sector 10 Head 0 Block 0 (Upper Surface) Cylinder 2 Block 8 (Lower Surface) Block 16 Block 32 Block 48 Physical Address= CHS Logical Block Address= Block# - 9 Disk Drive Performance: Seek Time Time taken to position the read/write head Lower the seek time, the faster the I/O operation Seek time specifications include: Full stroke Average Track-to-track

6 Disk Drive Performance: Rotational Speed/Latency The time taken by platter to rotate and position the data under the R/W head Depends on the rotation speed of the spindle Average rotational latency One-half of the time taken for a full rotation Appx. 5.5 ms for 5400-rpm drive Appx. 2.0 ms for rpm drive - 11 Disk Drive Performance: Data Transfer Rate Average amount of data per unit time Internal Transfer Rate Speed at which data moves from a track to disk internal buffer External Transfer Rate The advertised speed of the interface External transfer rate measured here Internal transfer rate measured here HBA Interface Buffer Head Disk Assembly Disk Drive

7 Why RAID Performance limitation of disk drive An individual drive has a certain life expectancy Measured in MTBF Example If the MTBF of a drive is 750,000 hours, and there are 100 drives in the array, then the MTBF of the array becomes 750,000 / 100, or 7,500 hours RAID was introduced to mitigate this problem RAID provides: Increase capacity Higher availability Increased performance - 13 RAID Array Components Physical Array Logical Array RAID Hard Disks RAID Array

8 RAID Implementations Hardware (usually a specialized disk controller card) Controls all drives attached to it Array(s) appear to host operating system as a regular disk drive Provided with administrative software Software Runs as part of the operating system Performance is dependent on CPU workload Does not support all RAID levels - 15 RAID Levels 0 Striped array with no fault tolerance 1 Disk mirroring Nested RAID (i.e., 1 + 0, 0 + 1, etc.) 3 Parallel access array with dedicated parity disk 4 Striped array with independent disks and a dedicated parity disk 5 Striped array with independent disks and distributed parity 6 Striped array with independent disks and dual distributed parity

9 Data Organization: Striping Stripe Strip Stripe Strip 1 Strip 2 Strip 3 Stripe 1 Stripe 2 Strips - 17 RAID RAID

10 RAID 1 Block 0 1 RAID Block Nested RAID 0+1 (Striping and Mirroring) RAID 1 Block 0 Block 2 Block RAID RAID 0 Block 1 Block

11 Nested RAID 0+1 (Striping and Mirroring) RAID 1 Block 0 Block 2 Block 0 Block 2 RAID RAID 0 Block 1 Block 3 Block 1 Block 3-21 Nested RAID 1+0 (Mirroring and Striping) RAID 0 Block 1 Block 3 Block 0 2 RAID RAID 1 Block 1 Block

12 Nested RAID 1+0 (Mirroring and Striping) RAID 0 Block 0 Block 1 Block 2 Block 3 RAID RAID 1 Block 0 Block 2 Block 1 Block 3-23 RAID Redundancy: Parity RAID 1? The middle drive fails: Parity calculation = ? + 7 = 18? = ? = 1 Parity Disk

13 RAID 3 Block RAID Block 0 Parity Block 1 Generated Block 2 Block 3 P RAID 5 Block 0 Block 4 Block 1 Block 5 Block 40 Parity RAID Block 04 Generated P Block 2 Block 6 Block 3 P P Block

14 RAID 6 Dual Parity RAID RAID-6 protects against two disk failures by maintaining two parities Horizontal parity which is the same as RAID-5 parity Diagonal parity is calculated by taking diagonal sets of data blocks from the RAID set members Even-Odd, and Reed-Solomon are two commonly used algorithms for calculating parity in RAID-6-27 Hot Spares RAID

15 STORAGE EVOLUTION LAN FC SAN Multi Protocol Router IP SAN RAID Array SAN / NAS JBOD Internal DAS TEMPO DATA PROCESS ORDER Client Server/ OS LAN BARRAMENTO Application User Interface DBMS system 15

16 DATA PROCESS ORDER IN SAN Client Server/ OS LAN FC SAN IP LAN FCOE Application User Interface DBMS Storage Array DAS Direct Attached Storage Internal DAS External DAS 16

17 NAS Network Attached Storage NETWORKED FILE SERVER PC stand alone PORTABLE MIDIA NETWORKED PCs NETWORKED STORAGE O que é NAS? SHARED STORAGE IN A LAN INFRASTRUCTURE 17

18 NAS COMPONENTS IPSAN ESTRUTURA SEM FCOE 18

19 Infra-estrutura futura com FCoE Components of an Intelligent Storage System Intelligent Storage System Front End Back End Physical Disks Connectivity Cache FC SAN

20 Intelligent Storage System: Front End Intelligent Storage System Front End Back End Physical Disks Connectivity Cache FC SAN Ports s - 39 Intelligent Storage System: Cache Intelligent Storage System Front End Back End Physical Disks Connectivity Cache FC SAN

21 Cache Management: Algorithms New Data Oldest Data Least Recently Used (LRU) Discards least recently used data Most Recently Used (MRU) Discards most recently used data - 41 Intelligent Storage System: Back End Intelligent Storage System Front End Back End Physical Disks Connectivity Cache FC SAN s Ports

22 Intelligent Storage System: Physical Disks Intelligent Storage System Front End Back End Physical Disks Connectivity Cache FC SAN - 43 What the Sees RAID Sets and LUNs 1 Intelligent Storage System LUN 0 Front End Back End Physical Disks Connectivity Cache LUN 0 FC SAN LUN 1 LUN

23 ISS Implementation: High-end Storage Systems Also referred as Active-active arrays I/O s are serviced through all the available path Following are high-end array capabilities: Large storage capacity Huge cache to service host I/Os Fault tolerance architecture Multiple front-end ports and support to interface protocols High scalability Ability to handle large amounts of concurrent I/Os Designed for large enterprises Active-Active Configuration Active Active Port Port A B LUN Storage Array - 45 Midrange Storage Systems Also referred as Active-passive arrays can perform I/Os to LUNs only through active paths Other paths remain passive till active path fails Midrange array have two controllers, each with cache, RAID controllers and disks drive interfaces Designed for small and medium enterprises Less scalable as compared to high-end array Active-Passive Configuration Active Port A B Port Passive LUN Storage Array

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